Singing Therapy for Rehabilitating Facial Mimicry in Parkinson's Disease: A Randomised Controlled Trial

Parkinson's disease can reduce facial expression and change the voice, making it harder to communicate emotions. This study examined whether practising facial and vocal imitation through speech and singing could improve facial expression and emotional communication in people with Parkinson's disease. Participants were assigned by chance to one of two 13-week programs. In Singing Imitation Therapy, participants watched and listened to recordings of emotional speech and song and copied the facial and vocal expressions. In Singing Observation Therapy, participants watched and listened to the recordings without being instructed to copy them. The main hypothesis was that imitation would lead to greater improvements in facial expression and automatic facial responses to other people's emotional expressions than observation alone.

Inclusion Criteria: Participants with Parkinson's disease: * Clinical diagnosis of idiopathic Parkinson's disease. * Aged 50-75 years at enrolment. * Parkinson's disease diagnosed at age 50 years or older. * At least eight years of English-speaking experience. * Provided written informed consent. Caregiver participants: * Informal caregiver of a participant enrolled in the Parkinson's disease treatment trial. * Provided separate informed consent to participate in questionnaire assessments. No separate age eligibility criteria were specified for caregiver participants. The stated age range of 50-75 years applies only to participants with Parkinson's disease. Exclusion Criteria: * Secondary or acquired parkinsonism. * Hoehn and Yahr stage greater than 4. * Clinically significant depressive symptoms, defined as a Beck Depression Inventory (BDI) score greater than 19. * Cognitive impairment, defined for screening as a Montreal Cognitive Assessment (MoCA) score below 21. * Severe visual or auditory deficits. * Concurrent participation in another treatment trial.